Sublimation of Li@C₆₀

Experiments that probe the fundamental properties of endohedral fullerenes often require the preparation of molecular beams or thin films of the neutral molecules. It is challenging to cleanly sublime this class of molecules without producing some thermal degradation. We report combined gas phase and scanning tunnelling microscopy studies that probe the thermal decay of commercial [Li⁺C₆₀]PF₆^- in a quartz ampoule and provide treatment conditions that will allow the sublimation of intact, neutral Li@C₆₀ accompanied by a well-characterised component of neutral C₆₀. The decay of the material at appropriate temperatures can be modelled with the assumption of a second order decay process in the oven yielding Arrhenius parameters that can predict the ratio of Li@C₆₀ to C₆₀ in the sublimed material.